Noun: An advocate of the supremacy of a particular group, especially one determined by race or sex
Adjective: Relating to or advocating the supremacy of a particular group
(source: Oxford Dictionary)

"The neo-fascists and white supremacists organized in groups like Hale's ‘Creativity’ movement are miniscule in number."
"They make clear their contempt for supremacist doctrine in ‘All the Young Fascists’."